At least 12 former faculty members at the elite Connecticut boarding school Choate Rosemary Hall engaged in “substantiated instances of sexual misconduct” with students dating back to the 1960s, the school said in a new report.

The report came as a result of an independent investigation led by investigator and former prosecutor Nancy Kestenbaum of Covington & Burling LLP after the school engaged the firm to conduct the investigation.

The investigation was announced two months after a former student wrote on a Choate alumni Facebook page about “two former teachers’ sexual misconduct, the impact it has had on her life, and her desire to see Choate take action with respect to reports of sexual misconduct, including her own,” the report said. The investigation announcement also came days after the Boston Globe published an article describing misconduct at Choate, among other schools.

In a letter last fall, Choate told the school community about the investigation and asked “anyone with possible knowledge of sexual misconduct by faculty or staff at Choate” to contact the school.

No reports were received relating to current Choate students and no reports of sexual misconduct were substantiated regarding any current faculty members or staff, the report said.

The report names the 12 former faculty members and details substantiated reports from male and female students. One faculty member reportedly assaulted a student repeatedly at the faculty member’s house in the mid-1990s. Another reported assault involving a different faculty member and two students happened during a school study abroad program in Costa Rica in 1999.

The greatest number of reports concerned “incidents in the 1980s, with roughly half that number in the 1970s and 1990s, and with significantly smaller numbers in the 1960s and 2000s,” the report said. A “handful of reports” were submitted about sexual misconduct in the 2010s.

“Certain Choate graduates described themselves as having been flattered, at the time,” by the attention from adults, but “later recognized that the conduct had been abusive,” the report said. “They described Choate faculty and staff engaging in acts with them that included intimate kissing, intimate touching and sexual intercourse.”

“Other graduates told us of contact that they recognized as abusive at the time, including forced or coerced intercourse, as well as other incidents of unwanted contact that led students to feel betrayed by faculty or staff they had trusted and admired,” the report said.

Many students who made these accusations didn’t tell the school at the time of the incidents, the report said; in some cases, the school was informed years later, and sometimes the school was notified in real time.

The report found that “sexual misconduct matters were handled internally and quietly.”

In nearly all the incidents, if the staff member still worked at Choate and was found to have violated school policy, the staff member was required to leave, the report said. “Sometimes the school moved quickly and decisively. In other cases, it was slower to respond and allowed the faculty member to remain at the school, sometimes with restrictions on his or her activity, for a considerable length of time,” the report said. “When a faculty member was a long-term and admired teacher, action sometimes came more slowly. On at least one occasion, a faculty member remained until his voluntary retirement, some 10 years after a student reported an incident of sexual misconduct.”

Choate said in a statement, “Choate is releasing the full contents of an independent investigator’s report consistent with its commitment to transparency and its pledge to be at the forefront of the highest standard of care in preventing and addressing adult sexual misconduct.”

The statement continued: “On behalf of Choate Rosemary Hall, we profoundly apologize. The conduct of these adults violated the foundation of our community: the sacred trust between students and the adults charged with their care. We honor and thank the survivors of sexual misconduct who came forward. We hope that through this report, our community can address the issue of adult sexual misconduct in a frank and direct manner. Throughout this self-examination, our goal has been to come together as a community to provide validation and support to those who suffered from abuse, to learn from the past, and to live up to the core standards outlined in Choate’s Statement of Expectations.”